Is this a move?

that already exists in some form? or did my friend invent something?

I will describe what transpired. This is a choke from when somebody is underhooking both your legs in order to stack you and pass your guard. Here's how it happened:

He had me in his rubber guard with his right hand holding his left ankle in the usual mission control manner. His rubber guard loosened up a little bit and I slipped both my arms under his legs to begin stacking and passing. He kept the rubber guard position, even though both of my arms were under his legs. He switched his hands on his ankle so that he was holding his left ankle with his LEFT hand, and his left forearm was jammed across the left side of my throat. He then figured foured his rubber guard leg with his right leg, just as you would with a normal triangle choke. So basically, he is doing a triangle just around my neck without an arm trapped and his own left forearm (the one that is holding his own ankle) is creating the pressure that normally would be created in a triangle choke by the person's own arm. He finished by pulling down my head with his right hand just as in a normal triangle choke.

Hope that wasnt too confusing.

In summary, it is a triangle choke without an arm, but using your own forearm to create pressure on one side of the neck.

It felt tight at the time, but havent gotten a chance to roll since in order to evaluate it further. Just thought I would see if this is some half ass variation of something that already exists.

yes eddie bravo invented it.its called the "french toast" its a transition from the "ham sandwhich" and you can also go for the "blt" from any position.lol